1. Field of the Invention
The present invention relates generally to medical devices and methods. More particularly, the present invention relates to apparatus and protocols for closing arteriotomies and other vascular wall penetrations.
Angiography, angioplasty, atherectomy, and a number of other vascular and cardiovascular procedures are performed intravascularly and require percutaneous access into the patient's vasculature, most often into the arterial vasculature. The most common technique for achieving percutaneous access is called the Seldinger technique, where access to an artery, typically the femoral artery in the groin, is first established using a needle to form a “tract,” i.e., a passage through the tissue overlying the blood vessel. The needle tract is then dilated, and an access sheath is placed into the dilated tract and through a penetration in the vascular wall, such as an arteriotomy to allow the introduction of guidewires, interventional catheters, catheter exchange, and the like to perform the desired procedure.
Once the desired procedure is completed, the access sheath must be removed and the arteriotomy or other vascular wall penetration closed. For many years, such closure was achieved by applying manual pressure onto the patient's skin over the site of the vascular wall penetration. Patients, however, have often been heparinized to limit the risk of thrombosis during the procedure, and clotting of the vascular wall penetration can often take an extended period, particularly when the penetration is relatively large for performing procedures needing larger diameter catheters. For these reasons, improved methods for closing and sealing vascular wall penetrations have been sought.
In the last decade, a variety of new procedures and devices have been introduced to more effectively seal the arteriotomies and other vascular wall penetrations associated with percutaneous intravascular access. Some of the new protocols rely on suturing, others rely on clipping, plug placement, energy-based closure, and the like. One problem with many of the new procedures, however, is that they leave material behind, and/or induce scar formation at the access site. Both the leaving of materials and the formation of scar tissue can be problematic, particularly if the patient requires subsequent access to the same vascular site for performance of another vascular or cardiovascular procedure.
For these reasons, it would be advantageous to provide protocols and apparatus which would leave no material behind and which would further limit the likelihood of forming scar tissue after the procedure is complete. One device that can meet these objectives in many instances is the Boomerang Catalyst™ system available from Cardiva Medical, Inc., assignee of the present application. The Boomerang Catalyst system includes an expansible element at its tip for providing temporary hemostasis when placed in the blood vessel adjacent to the vascular wall penetration. The catheter further includes a catalytic material on its shaft which helps induce hemostasis and clotting within the tissue tract immediately above the vessel wall penetration. The construction and use of this system is described in copending application Ser. No. 11/302,951; Ser. No. 11/772,718; and Ser. No. 11/614,276, the full disclosures of which are incorporated herein by reference.
Despite the success of the Boomerang Catalyst systems, there may still be some instances where hemostasis is not achieved as rapidly. For this reason, it would be desirable to provide further improved systems and protocols for closing and sealing arteriotomies and other vascular wall penetrations, where the closure may be achieved with rapid hemostasis, with a minimum risk of scar formation, and without leaving any materials or implants permanently behind in the vessel or the tissue tract. At least some of these objectives will be met by the inventions described below.
2. Background of the Invention
U.S. Pat. No. 7,335,219 describes a device for delivering a plug of hemostatic material to a location just above a blood vessel wall penetration. The hemostatic material is encapsulated in a dissolvable structure and a non-expandable control tip assembly helps advance the device through the tissue tract and may also provide hemostasis and bleedback. US2007/0123817 and U.S. Pat. No. 7,008,439 describe apparatus for sealing a vascular wall penetration. Other apparatus for closing blood vessel wall punctures are described in U.S. Pat. Nos. 4,744,364; 5,061,271; 5,728,133; and 7,361,183 and U.S. Published Patent Application Nos. 2003/0125766; 2004/0267308; 2006/0088570; 2007/0196421; and 2007/0299043. The incorporation of anti-proliferative materials in hemostatic materials for blood vessel closure and other purposes is described in U.S. Pat. Nos. 7,025,776 and 7,232,454; 6,554,851; and U.S. Published Patent Application Nos. 2005/0004158; 2005/0038472; 2007/0060895/2007/0032804; and 2008/0039362.